Re: [PATCH v6 4/5] virtio-iommu-pci: Add array of Interval properties

[Markus Armbruster]

Eric Auger <eric.auger@redhat.com> writes:

> The machine may need to pass reserved regions to the
> virtio-iommu-pci device (such as the MSI window on x86
> or the MSI doorbells on ARM).
>
> So let's add an array of Interval properties.
>
> Note: if some reserved regions are already set by the
> machine code - which should be the case in general -,
> the length of the property array is already set and
> prevents the end-user from modifying them. For example,
> attempting to use:
>
> -device virtio-iommu-pci,\
>  len-reserved-regions=1,reserved-regions[0]=0xfee00000:0xfeefffff:1
>
> would result in the following error message:
>
> qemu-system-aarch64: -device virtio-iommu-pci,addr=0xa,
> len-reserved-regions=1,reserved-regions[0]=0xfee00000:0xfeefffff:1:
> array size property len-reserved-regions may not be set more than once
>
> Otherwise, for example, adding two reserved regions is achieved
> using the following options:
>
> -device virtio-iommu-pci,addr=0xa,len-reserved-regions=2,\
>  reserved-regions[0]=0xfee00000:0xfeefffff:1,\
>  reserved-regions[1]=0x1000000:100ffff:1
>
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>
> ---
> v5 -> v6:
> - check the type value
> - removed Jean's R-b
>
> v3 -> v4:
> - added examples in the commit message as suggested by Markus
> - added Jean's R-b
> ---
>  hw/virtio/virtio-iommu-pci.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
>
> diff --git a/hw/virtio/virtio-iommu-pci.c b/hw/virtio/virtio-iommu-pci.c
> index 632533abaf..9c9bda9490 100644
> --- a/hw/virtio/virtio-iommu-pci.c
> +++ b/hw/virtio/virtio-iommu-pci.c
> @@ -33,6 +33,9 @@ struct VirtIOIOMMUPCI {
>  
>  static Property virtio_iommu_pci_properties[] = {
>      DEFINE_PROP_UINT32("class", VirtIOPCIProxy, class_code, 0),
> +    DEFINE_PROP_ARRAY("reserved-regions", VirtIOIOMMUPCI,
> +                      vdev.nb_reserved_regions, vdev.reserved_regions,
> +                      qdev_prop_reserved_region, ReservedRegion),
>      DEFINE_PROP_END_OF_LIST(),
>  };
>  
> @@ -40,6 +43,7 @@ static void virtio_iommu_pci_realize(VirtIOPCIProxy 
> *vpci_dev, Error **errp)
>  {
>      VirtIOIOMMUPCI *dev = VIRTIO_IOMMU_PCI(vpci_dev);
>      DeviceState *vdev = DEVICE(&dev->vdev);
> +    VirtIOIOMMU *s = VIRTIO_IOMMU(vdev);
>  
>      if (!qdev_get_machine_hotplug_handler(DEVICE(vpci_dev))) {
>          MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
> @@ -54,6 +58,15 @@ static void virtio_iommu_pci_realize(VirtIOPCIProxy 
> *vpci_dev, Error **errp)
>                            "-no-acpi\n");
>          return;
>      }
> +    for (int i = 0; i < s->nb_reserved_regions; i++) {
> +        if (s->reserved_regions[i].type != VIRTIO_IOMMU_RESV_MEM_T_RESERVED 
> &&
> +            s->reserved_regions[i].type != VIRTIO_IOMMU_RESV_MEM_T_MSI) {
> +            error_setg(errp, "reserved region %d has an invalid type", i);
> +            error_append_hint(errp, "Valid values are "
> +                              "VIRTIO_IOMMU_RESV_MEM_T_RESERVED and "
> +                              "VIRTIO_IOMMU_RESV_MEM_T_SMI\n");

Actually, valid values are 0 and 1.  Something like

    -device 
virtio-iommu-pci,len-reserved-regions=1,reserved-regions[0]=0xfee00000:0xfeefffff:VIRTIO_IOMMU_RESV_MEM_T_SMI

will be rejected as invalid.

> +        }
> +    }
>      object_property_set_link(OBJECT(dev),
>                               OBJECT(pci_get_bus(&vpci_dev->pci_dev)),
>                               "primary-bus", errp);

Sorry for having to torture you this way!  Have a
Reviewed-by: Markus Armbruster <armbru@redhat.com>
with the error message touched up.